The flavour of foodstuffs and beverages consists of two parts: the aroma and the taste. In general what is perceived through the olfactory epithelium in the nasal cavity is referred to as ‘aroma’, whereas the term ‘taste’ is generally used to describe the sensory impact that is perceived via the mouth, especially the tongue. The flavour sensation experienced upon consumption, especially the taste, provides the final analysis of food prior to ingestion thereof. Visual and olfactory (smell) signals already give a first indication but only after intake of the food into the mouth the final decision is made either to ingest or to reject the food. Sweet taste is usually a signal that the food is safe (appetising) leading to ingestion of the food. The ‘reactions’ to salt and umami are really dependent on the strength of the signal. Bitter and sour are usually experienced as repulsive taste sensations that can lead to rejection. Temperature is another measure by which the food is judged just as well as aching sensations like capsaicin (hot pepper) and certain chemicals (like carbon dioxide).
In short, this means that taste is a very important and very complex system. Until recently most flavour research was focused towards aroma. Especially the last years a series of publications relating to molecules with a (positive) contribution to the taste of foodstuffs has emerged.
Such research has been stimulated significantly by the fact that quite some receptors which are involved in the different taste sensations have been characterized by now (B. Lindemann; Nature 413, 219 (2001)).
Another interesting aspect of taste is that it can have an impact on aroma. It was reported that people having artificially sweetened water in their mouth were significantly more sensitive to the smell of benzaldehyde than people having plain water in their mouth (P. Dalton et al, Nature Neurosci. 3, 431-432 (2000)).
Several screening systems have been described that make it possible to screen, in a short time, large series of molecules for their (modulating) effect on taste response (cf. WO04055048, GB2396414, WO0177292 and US2004/0072254).
Most research on taste modulation so far has been devoted to taste enhancement in savoury products. Several, mainly Japanese, publications describe umami molecules, i.e. alternatives to mono sodium glutamate (MSG) (H Suzuki et al, J Agric Food Chem 50, 313-318 (2002); K Shima et al, J Agric Food Chem 46, 1465-1468 (1998); Y Ueda et al, Biosc Biotech Biochem 61 1977 (1997)).
In EP 1291342, a ‘general taste enhancer’ is disclosed that was reported to be suitable for enhancing sweetness as well.
Alpha keto acids are reported to give body and mouthfeel to foodstuffs they are added to (U.S. Pat. No. 6,287,620).
Chlorogenic acids are claimed to enhance sweetness and to reduce bitterness (WO02100192).
WO 97/04667 relates to certain tripeptides as well as to substances that include an N-lactoyl radical and a residue of one of the common amino acids. These so-called N-lactoyl-X type substances, wherein X represents the amino acid residue, are deemed to have the following structural feature in common, R′ representing the side chain of one of the 20 proteogenic amino acids:
The tripeptides and N-lactoyl-X type substances according to WO 97/04667 were found to constitute useful flavouring ingredients. According to this document these flavouring ingredients are capable of improving the oral perception or mouthfeel of products to which they are added and producing organoleptic effects of the type of that which can be obtained using MSG.
WO04/075663 concerns the use of derivatives of dicarboxylic acids and amino acids as flavouring ingredients, more particularly as mouthfeel and/or umami agents and/or as MSG partial or total replacers. WO 04/075663 teaches the following common structure of these derivatives:
wherein G represents a linear C1-C6 alkyl group, in particular CH2, CH2CH2 or CH2CH2CH2, or a HC═CH group, and R′ represents the side chain of one of the 20 proteogenic amino acids.
There is still a need for new so-called flavour modulating substances that provide a positive contribution to the flavour, especially the taste, of foodstuffs, beverages, orally administered pharmaceuticals, tobacco products and oral care products they are incorporated in. One objective of the present invention is to provide such substances and compositions comprising them.